Semiconductor power module, production method of semiconductor power module and circuit board

Abstract

A semiconductor power module ( 10 ) includes a ceramic multilayer substrate ( 100 ), a bonding layer ( 110 ), a diffusion layer ( 120 ) and a semiconductor device ( 130 ). The bonding layer is placed on a first surface ( 105 ) of the ceramic multilayer substrate and is provided as a planar thin film layer including conductive bonding parts ( 111 ) configured to electrically connect the semiconductor device with the ceramic multilayer substrate and insulating bonding parts ( 112 ) configured to isolate the semiconductor device from the ceramic multilayer substrate. Also disclosed is a production method of the semiconductor power module.

1 . A semiconductor power module comprising:
 a multilayer substrate having a via and an interconnecting pattern formed thereon;   a semiconductor device placed on a first surface side of the multilayer substrate; and   a bonding layer formed on the first surface of the multilayer substrate for bonding the multilayer substrate to the semiconductor device, wherein   the bonding layer includes:
 a planar conductive bonding part arranged at a first region corresponding to the via and configured to have a conductive projection formed on the semiconductor device and a conductive connector arranged to provide electrical continuity between the projection and the multilayer substrate; and 
 a planar insulating bonding part arranged at a second region different from the first region and made of an inorganic material as a main constituent. 
   
     
     
         2 . The semiconductor power module according to  claim 1 , wherein
 the multilayer substrate and the bonding layer are bonded by diffusion bonding, and the semiconductor device and the bonding layer are bonded by diffusion bonding, and   the semiconductor power module further comprises:   a diffusion layer formed between the multilayer substrate and the bonding layer and between the semiconductor device and the bonding layer during the diffusion bonding.   
     
     
         3 . The semiconductor power module according to  claim 1 , wherein
 a first bonding start temperature which is a bonding start temperature of a material constituting the conductive bonding part is lower than a second bonding start temperature which is a bonding start temperature of a material constituting the insulating bonding part.   
     
     
         4 . The semiconductor power module according to  claim 3 , wherein
 the first bonding start temperature is equal to or higher than a sintering start temperature at which at least part of the material constituting the conductive bonding part starts a sintering reaction, and   the second bonding start temperature is equal to or higher than a sintering start temperature at which at least part of the material constituting the insulating bonding part starts a sintering reaction.   
     
     
         5 . A production method of a semiconductor power module comprising:
 a substrate manufacturing step that manufactures a multilayer substrate having a via and an interconnecting pattern;   a first placement step that places a bonding part on a first surface of the multilayer substrate, wherein the bonding part has a planar conductive connector for providing electrical continuity between the interconnecting pattern and a semiconductor device at a first region corresponding to the via and a planar insulating bonding part at a second region different from the first region;   a second placement step that places the semiconductor device on the bonding part such as to provide electrical continuity between a conductive projection formed on the semiconductor device and the conductive connector; and   a bonding step that bonds the multilayer substrate, the bonding part and the semiconductor device by application of heat and pressure, so as to make diffusion bonding between the multilayer substrate and the bonding part and between the bonding part and the semiconductor device.   
     
     
         6 . The production method of the semiconductor power module according to  claim 5 , wherein
 a first bonding start temperature is a temperature at which a material constituting the conductive connector starts bonding to the semiconductor device, and   a second bonding start temperature is a temperature at which a material constituting the insulating bonding part starts bonding to the multilayer substrate and to the semiconductor device and which is higher than the first bonding start temperature, wherein   the bonding step includes:
 a step of bonding the multilayer substrate, the bonding part and the semiconductor device by application of pressure and heat at the first bonding start temperature, so as to bond the conductive connector to the projection of the semiconductor device; and 
 a step of bonding the multilayer substrate, the bonding part and the semiconductor device by application of pressure and heat at the second bonding start temperature, so as to bond the multilayer substrate to the bonding part and bond the bonding part to the semiconductor device, after the conductive connector is bonded to the projection of the semiconductor device. 
   
     
     
         7 . The production method of the semiconductor power module according to  claim 6 , wherein
 the first bonding start temperature is equal to or higher than a sintering start temperature at which at least part of the material constituting the conductive connector starts a sintering reaction, and   the second bonding start temperature is equal to or higher than a sintering start temperature at which at least part of the material constituting the insulating bonding part starts a sintering reaction.   
     
     
         8 . The production method of the semiconductor power module according to  claim 5 , wherein
 a first bonding start temperature is a temperature at which a material constituting the conductive connector starts bonding to the semiconductor device, and   a second bonding start temperature is a temperature at which a material constituting the insulating bonding part starts bonding to the multilayer substrate and to the semiconductor device and which is higher than the first bonding start temperature, wherein   the bonding step performs the application of heat, based on a temperature profile which is set to maintain the first bonding start temperature for a predetermined time and subsequently maintain the second bonding start temperature for a predetermined time.   
     
     
         9 . The production method of the semiconductor power module according to  claim 5 , wherein
 the first placement step includes:
 a step of placing the insulating bonding part having an opening portion at the first region on the first surface; and 
 a step of placing the conductive connector made thinner than the insulating bonding part in the opening portion, and 
   the second placement step includes:
 a step of placing the semiconductor device on the bonding part such that the projection is fit in the opening portion, so as to provide electrical continuity between the projection of the semiconductor device and the conductive connector, and wherein 
   d3>d2−d1 is satisfied where d1 represents a thickness of the conductive connector, d2 represents a thickness of the insulating bonding part and d3 represents a height of the projection.   
     
     
         10 . The production method of the semiconductor power module according to  claim 9 , wherein
 the step of placing the insulating bonding part arranges the insulating bonding part to be in such a shape that narrows from an end bonded to the semiconductor device toward an end bonded to the multilayer substrate.   
     
     
         11 . The production method of the semiconductor power module according to  claim 10 , wherein
 the step of placing the insulating bonding part arranges the insulating bonding part to be in a tapered shape.   
     
     
         12 . A circuit board substrate comprising:
 a multilayer substrate having a via and an interconnecting pattern formed thereon; and   a bonding layer formed on a first surface of the multilayer substrate for bonding the multilayer substrate to a semiconductor device, wherein   the bonding layer includes:
 a conductive connector arranged at a first region corresponding to the via and configured to provide electrical continuity with the interconnecting pattern and with the semiconductor device, wherein at least a first surface-side surface of the conductive connector is made planar; and 
 an insulating bonding part arranged at a second region different from the first region and made of an inorganic material as a main constituent, wherein at least a first surface-side surface of the insulating bonding part is made planar. 
   
     
     
         13 . The circuit substrate according to  claim 12 , wherein
 the conductive connector is made thinner than the insulating bonding part, and   the bonding layer has a recess formed by the insulating bonding part and the conductive connector, and wherein   before a conductive projection formed on the semiconductor device is fit in the recess, d3>d2−d1 is satisfied where d1 represents a thickness of the conductive connector, d2 represents a thickness of the insulating bonding part and d3 represents a height of the projection.   
     
     
         14 . The circuit substrate according to  claim 12 , wherein
 the insulating bonding part is formed in such a shape that narrows from an end bonded to the semiconductor device toward an end bonded to the multilayer substrate.   
     
     
         15 . The circuit substrate according to  claim 12 , wherein
 the insulating bonding part is formed in a tapered shape.